How Accurate Are FBI’s Estimated Crime Data?

Some police agencies report no data for the FBI’s annual report of reported U.S. crime. Should the agency report margins of error?

Every year, more than 18,000 police agencies are asked to submit crime data to the FBI. Some don’t provide complete information or any information at all. When that happens, the FBI uses crude estimates to account for the missing data, the Wall Street Journal reports. Those figures are then used to generate “Crime in the United States,”an annual tally of violent and property crimes that is a quality-of-life measure as well as a gauge of criminal justice policies and spending. In most instances, the estimates don’t stray substantially from the submitted numbers.

In its latest report, the FBI didn’t adjust the counts of reported violent crime for 11 states at all. It inflated Indiana’s numbers by 9.9 percent, West Virginia’s by 13 percent and Mississippi’s by 68 percent raising that state’s count to an estimated 8,526, up from a reported 5,084. Homicides showed similar discrepancies. The numbers for 28 states were not adjusted, but Mississippi’s count was increased by 56 perceent to an estimated 245 murders from a reported 157. Jeff Asher, a crime analyst based in New Orleans, argues the agency should publish margins of error with its numbers. James Alan Fox, a criminologist at Northeastern University, said the numbers are close enough to evaluate trends over multiple years. “The problem is looking one year to the next,” he said. “Don’t get hung up on the year-to-year changes.” Others believe the FBI should use a more sophisticated system for generating estimates. Two decades ago,  the U.S. Bureau of Justice Statistics published a 78-page paper critiquing the FBI’s procedure and recommending ways to improve it. “So far, nothing has come of it,” said Michael Maltz of Ohio State University, who wrote the paper. Alicia Carriquiry, a statistician at Iowa State University, suggests devising a system that would take advantage of all of available data, not only across agencies but across time.